1620880 has 20 divisors (see below), whose sum is σ = 3768732. Its totient is φ = 648320.

The previous prime is 1620841. The next prime is 1620881. The reversal of 1620880 is 880261.

It can be written as a sum of positive squares in 2 ways, for example, as 219024 + 1401856 = 468^2 + 1184^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (1620881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10051 + ... + 10210.

2^1620880 is an apocalyptic number.

1620880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1620880 is an abundant number, since it is smaller than the sum of its proper divisors (2147852).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1620880 is a wasteful number, since it uses less digits than its factorization.

1620880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20274 (or 20268 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 1620880 is about 1273.1378558507. The cubic root of 1620880 is about 117.4672913333.

It can be divided in two parts, 1620 and 880, that added together give a square (2500 = 50²).

The spelling of 1620880 in words is "one million, six hundred twenty thousand, eight hundred eighty".